This file photo shows a Japanese subway employee bowing next to a train after a safety check in a subway station in central Tokyo on October 12, 2016. (Photo by AFP)

A huge power cut following a fire at a facility has struck the Japanese capital, knocking out power to about 580,000 homes and big office and government buildings.

The power outage occurred on Wednesday just before the evening rush hour, which also brought two train lines to a halt.

Officials said the cause of the fire at an underground facility run by utility Tokyo Electric Power (TEPCO) was not immediately known.

Television footage showed plumes of black smoke billowing from street-side grates linked to the facility in Niiza City, north of Tokyo.

This picture shows a view of Tokyo Electric Power Co. (TEPCO) headquarters in Tokyo on February 29, 2016. (Photo by AFP)

The outage affected some central government buildings and downtown office towers, including the landmark Marunouchi Building, in the economic heart of Japan.

Tokyo's metropolitan police department, the land and transportation ministry and the foreign ministries were among the government offices that briefly lost power while traffic lights were out in some locations.

There were no immediate reports of injuries but the Tokyo Fire Department said they had received reports from people trapped inside elevators and were assessing the situation.

Chief Cabinet Secretary Yoshihide Suga told a news conference that officials were looking into the cause of the incident. He did not rule out the possibility of sabotage, according to the NHK broadcaster.